1. Field of the Invention
The present invention relates generally to systems that manage fleets of vehicles. More particularly, the present invention relates to a multi-mode in-vehicle control unit for transmitting vehicle data to a processing center to support fleet management functions.
2. Background of the Invention
Many companies use a fleet of vehicles to transport personnel, equipment and/or packages to a particular destinations. For example, companies in service industries have a fleet of vehicles to carry service technicians and equipment to customer locations in response to service requests or reports of service disruption received from customers. Delivery companies such as Federal Express, UPS and DHL use fleets of vehicles to transport packages between drop and destination locations. Utility companies, including power and telephone companies, use a fleet of vehicles to transport technicians and equipment to install, repair and maintain services for customers.
Any company that relies on a fleet of vehicles to render its services can benefit greatly if the vehicles in its fleet can be managed efficiently. Managing a fleet of vehicles efficiently requires that the management system obtain information on the status of each vehicle in the fleet. Information related to the status of a vehicle, as explained in the '368 application, includes location, speed, time stationary, distance traveled and other status indicators.
This status information can be forwarded to a processing center, which uses the status information to better route vehicles in the fleet to meet service demands. For example, vehicle schedules can be generated to route vehicles to destinations according to a logical dispatch scheme. The status information is monitored during the lifetime of the vehicle or as often as required to meet a specific application. Occurrences termed “events” trigger recording and transmission of status information. Events include vehicle movement, ignition on/off, vehicle speed, vehicle stopping and other events. There can be up to 160 or 180 events collected per vehicle per day. Events are described in more detail in the '368 application.
Status information collected by the vehicle in response to an event is forwarded over a wireless transmission network to a processing center for processing. Transmission networks for sending this data include wireless data systems, cellular systems and satellite systems. For cost reasons, wireless data systems are generally preferred. Using a wireless data system, the status information can be sent cost-effectively in real-time or near real-time. However, conventional wireless data systems are generally limited in terms of their coverage area and capacity. Often, therefore, wireless data systems cannot fully service large companies' status information transmission needs.
Satellite and cellular telephone systems generally provide greater coverage areas than wireless data systems. However, the costs associated with satellite and cellular telephone systems to transmit status information collected by vehicles in a companies' vehicle fleet is generally economically unfeasible. For example, consider a company fleet having 10,000 vehicles. In this example, the companies' fleet management system records status information each time the vehicle travels a half mile or each time a vehicle travels for a duration of five minutes. That is, in this exemplary system, travel distance of a half mile and travel duration of five minutes are events. In a cellular telephone network-based system, a cellular telephone is made to send the collected status information to the processing center for each occurrence of these events for each of the 10,000 vehicles in the fleet. Sending all of this data to the processing center on a real-time or near real-time basis for each of the 160 to 180 events occurring in each of the 10,000 vehicles in the fleet would, in all likelihood, require a full day of cellular air charges. Such charges generally are uneconomical due to the high cost of cellular air time.